1. Field of the Invention
The present invention relates to aluminum nitride powder suitable as a member for a semiconductor manufacturing equipment such as a heater material and an electrostatic chuck and a method of manufacturing the aluminum nitride powder.
2. Description of the Related Art
Conventionally, aluminum nitride (AlN) has been widely used as a member for a semiconductor manufacturing equipment such as a heater material for heating a semiconductor wafer and an electrostatic chuck since AlN exhibits high-corrosion resistance to a halogen gas. Meanwhile, aluminum nitride is desired to have high insulating properties when used as a heater material, whereas a volume resistivity of about 109 to 1012 Ω·cm when used as a material for an electrostatic chuck. However, since the volume resistivity of aluminum nitride decreases to 107 Ω·cm or less in a high temperature atmosphere of 500° C. or more, the insulating properties of aluminum nitride cannot be ensured in the high temperature atmosphere. Based on the background, attempts to improve the volume resistivity of aluminum nitride under a high temperature atmosphere by adding MgO or B4C to aluminum nitride have been made as disclosed in Japanese Patent Application Laid-open Nos. 2000-44345, 2003-221279, and 2003-226580. However, alkaline earth elements (Mg) or Boron (B) may cause contamination of semiconductor wafers. Due to the possibility of such an adverse effect, it is not always desirable to add alkaline earth elements or Boron to aluminum nitride to improve the volume resistivity thereof in a semiconductor manufacturing process.
The present invention has been achieved to solve the above problem, and an object of the present invention is to provide aluminum nitride powder capable of improving the volume resistivity thereof under a high-temperature atmosphere without adding an alkaline earth elements or Boron, and a method of manufacturing the aluminum nitride powder.